Quasiballistic phonon transport from first principles
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2020-10-26 |
| Journal | Physical review. B./Physical review. B |
| Authors | Pol Torres, Miquel Royo, Miquel LĆ³pez-SuĆ”rez, Junichiro Shiomi, Riccardo Rurali |
| Institutions | Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari, Institut de CiĆØncia de Materials de Barcelona |
| Citations | 9 |
Abstract
Section titled āAbstractāAt short length scales phonon transport is ballistic: the thermal resistance of semiconductors and insulators is quantized and length independent. At long length scales, on the other hand, transport is diffusive and resistance arises as a result of the scattering processes experienced by phonons. In many cases of interest, however, these two transport regimes coexist. Here we propose a first-principles approach to treat quasiballistic phonon transport where diffusive and ballistic phonons receive separate theoretical treatments. Partitioning the overall phonon population for a given transport length is performed examining the mean free paths obtained from the solution of the Boltzmann transport equation and allowing only diffusive phonons to participate in anharmonic phonon-phonon scattering processes. We present results for Si and diamond, discussing the crossover from ballistic to diffusive transport as the length scale and/or the temperature increases and compute the relative contribution of ballistic and diffusive phonons to the thermal conductance in each transport condition.